Internal combustion engines with direct fuel injection are known. Piezo injectors, the nozzle needle of which is driven by a piezo actuator, are used for the direct fuel injection. Here a coupling virtually free of play is required between the piezo actuator and the nozzle needle, but this coupling is difficult to maintain due to thermally induced variations in length in the piezo injector. Insufficient play between the piezo actuator and the nozzle needle may result in incomplete closure of a nozzle needle. Excessive play between the piezo actuator and the nozzle needle may lead to an increase in the actuation energy needed to actuate the piezo injector. In the state of the art attempts have been made to compensate for thermally induced variations in length through a suitable choice of materials and geometry. This leads to high production costs, however, and severely restricts the design freedom in designing the piezo injector.